I've finally caught up with the current state of the database (not counting the current incomplete month). The count now stands at 99959 puzzles and that's not mentioning the fact that they underwent a more scrutinizing process than before and that more false positives have been removed as well.

By writing a function that, in the vast majority of cases, can rule out the possibility of immobilizing the opponent with the current move, I've been able to mine the games for all unique wins-in-2 (except those involving repetition) in a reasonable amount of time. With possibly a few exceptions, the puzzle database should now be both complete and correct, including with respect to immobilization.

In addition, I've been maintaining a scoreboard of some sort, which, for each player, shows how often they actually played the correct move when these positions occurred and, probably more informatively, the most recent such puzzle they didn't solve over the board.

That scoreboard is nice (although I don't like my position on it...). Could you also add a column with number of games lost after missing the unique win-in-2? (and a button to exclude bots from the table would also be great btw).